The present invention relates to a device to assist in the therapy of a patient and, in particular, to a patient who has limited jaw opening due to any number of causes such as muscle injury, surgical procedures, radiation therapy, temporomandibular joint dysfunction, osteoarthritis, post infection, or trauma.
There are many persons who are limited in the extent to which they are able to open their mouths. Some of the causes of this problem are listed above. This problem is frequently referred to as trismus. A person afflicted with trismus is not able to fully open their lower jaw. This is problematic in that, often, access to the interior of the afflicted person""s mouth and throat is necessary to effectively treat the cause of the affliction. Approximately 75,000 to 100,000 persons in the United States require treatment for this ailment annually.
Additionally, there are other occasions, such as during an examination or any procedure performed with or without general or local anesthesia, when the patient""s mouth must be propped open.
The applicants are aware of devices for dilating and/or propping open a human mouth. The Dingman Mouth Gag is a frame with coiled springs, tongue depressors, cheek retractors and movable tooth hooks which is positioned in front of the mouth. In U.S. Pat. No. 742,698 to Mason, a dental prop is disclosed which has pivoted jaws and tooth pads on the inner ends of the jaws. Arthur, in U.S. Pat. No. 972,983 discloses a dilator having a handle with four sockets in which are received four blades. The handle may be turned to move the blades. Koehler, in U.S. Pat. No. 976,812 discloses a mouth speculum having a pair of pivotally connected jaw bars which have ends to engage teeth within a mouth. Rotation of a bolt provides a means to open and close the jaws. In U.S. Pat. No. 1,025,265, Grindle discloses a cheek distender having two pivotally connected handles with bow-shaped arms and cheek plates on the ends of the arms. In U.S. Pat. No. 1,229,595, Du Brul discloses a dental appliance having a prop to hold the mouth open. The appliance has two sections connected by a spring hinge. A plate is attached to one section to engage the teeth. The other section has means to hold a clam roll in place. In U.S. Pat. No. 1,311,313 Brix discloses a retractor having two parallel bars spaced apart by an arm at one end and a plate at the other. A movable arm is carried by one of the parallel bars. Hooks are formed on the ends of the arms. A slidable bar is connected to the other parallel bar. On the end of the slidable bar is a hook which can be moved with respect to the parallel bars. In U.S. Pat. No. 2,061,936 issued to Engelfried, a mouth prop is disclosed that is inserted between a patient""s teeth. This device includes a threaded bolt that carries a pair of bars thereon that, carrying tooth engagement means thereon, are linearly movable to prop a mouth open. In U.S. Pat. No. 2,182,390 issued to Reardon, a surgical device is disclosed for propping open the mouth of a patient, so as to permit access to and illumination of the area in back of the nose and above the palate. In U.S. Pat. No. 5,718,665, Stubbs discloses an animal speculum wherein first and second arms connected by a threaded rod are provided. By rotating the rod, the distance between the first and second arms may be selectively adjusted. In U.S. Pat. No. 5,846,212, Beeuwkes, III et al disclose a device for omnidirectional translation of the mandible of a human patient. The device provides for translation and lateral movement. Kastenbauer et al, in U.S. Pat. No. 5,897,491 disclose a device for endoscopic examination which includes a vertical frame with locking and vertical frame with locking and spreading instruments attached to the frame and extending horizontally from the frame. Esselbach, in UK Patent 17.220 discloses a mouth opening instrument having angularly bent levers hinged together. The ends of the arms of the levers carry mouthpieces which are spring actuated into an open position. Schranz, in UK Patent 674.272 discloses a retractor which has two curved arms which are pivotally connected to a bridge member. Each curved arm has a shortened arm which is received in a central traveling block. A gear box is mounted in the center of the bridge member. The curved arms open and close.
While being useful for their purpose, most of these patented devices have particular drawbacks, especially where the patient is afflicted with trismus. In particular, the jaw supporting portions move away from and towards one another in a straight linear fashion. Unfortunately, the mandible does not move in such a linear fashion. The jaw joint is a ginglimoarthroidial joint and, as such, moves in a sliding pivotal articulation (where the lower jaw joins the skull), such that the lower jaw pivotally moves away from and towards the skull in a substantially arcuate path. Thus, if the devices such as disclosed in Engelfried and Reardon would be utilized to open a jaw afflicted with trismus, the tooth engaging portions thereof, while moving linearly, would slip or ride over the teeth of the jaw, which moves arcuately. Such an arrangement can result in breaking and/or other damage occurring to the teeth and/or jaw of the patient.
U.S. Pat. No. 5,035,420 to Beeuwkes, III et al, disclose a jaw exerciser which has curvilinear guide tracks to guide movement of a carriage which provides corresponding movement of a mandibular jaw member. The mandibular jaw member is supported by the carriage.
U.S. Pat. Nos. 4,991,566 and 5,097,820 to Shulman et al address the arcuate movement of the jaw and disclose devices which move similarly to the natural movement of the jaw. However, the devices can be substantially improved and the present application discloses improvements to these devices.
It is a primary object of the present invention to provide a device for opening the jaw of a patient in therapy of the patient.
It is a further object to provide a jaw opening device in which the tension applied to the jaw can be varied quantitatively and in small, controllable increments.
In accordance with the teachings of the present invention, there is disclosed a device to assist in the therapy of a patient who has limited jaw opening. The device has a rectangular frame having two opposite side members. The side members have adjustable lengths. Means are provided to adjust the lengths of the side members concurrently. Each side member has a first end and an opposite second end. An upper mouthpiece and a lower mouthpiece are connected between the respective first end of the side members of the frame. The upper mouthpiece and the lower mouthpiece have a distance therebetween wherein adjusting the lengths of the side members of the frame changes the distance between the upper mouthpiece and the lower mouthpiece. When the mouthpieces are received in the mouth of the patient, the jaw opening of the patient is adjustable.
In further accordance with the teachings of the present application, there is disclosed a device to assist in the therapy of a patient who has limited jaw opening. The device has a frame having two side members, the side members having adjustable lengths. Each side member has a first end and an opposite second end. Means are provided to adjust the lengths of the side members concurrently. An upper mouthpiece and a lower mouthpiece are connected between the respective first ends of the side members of the frame, the upper mouthpiece and the lower mouthpiece having a distance therebetween. Each side member has a center bore formed longitudinally therethrough. A spring is disposed in each bore, the spring having a first end and a second end. An adjusting means is connected to the first end of each spring. A chuck tip is connected to the second end of each spring. Two heads are provided, the first end of each side member being connected to a respective one of the heads. Each head has an opening therein. A respective joint is received in each opening in the respective heads. A cam surface is formed on each joint, the respective chuck tip bearing on the cam surface. Two spaced-apart sleeves are provided, the respective second ends of each side member being telescopically received in the respective sleeve. Changing the adjusting means on the first end of each spring changes the tension of the respective springs with respect to the cam surface and telescopically moves the respective side members with respect to the sleeves. In this manner, the distance between the upper mouthpiece and the lower mouthpiece is changed, such that the jaw opening of the patient is adjustable in controllable increments.
These and other objects of the present invention will become apparent from a reading of the following specification taken in conjunction with the enclosed drawings.